1========================================
2Libc++ 8.0.0 (In-Progress) Release Notes
3========================================
4
5.. contents::
6   :local:
7   :depth: 2
8
9Written by the `Libc++ Team <https://libcxx.llvm.org>`_
10
11.. warning::
12
13   These are in-progress notes for the upcoming libc++ 8 release.
14   Release notes for previous releases can be found on
15   `the Download Page <https://releases.llvm.org/download.html>`_.
16
17Introduction
18============
19
20This document contains the release notes for the libc++ C++ Standard Library,
21part of the LLVM Compiler Infrastructure, release 8.0.0. Here we describe the
22status of libc++ in some detail, including major improvements from the previous
23release and new feature work. For the general LLVM release notes, see `the LLVM
24documentation <https://llvm.org/docs/ReleaseNotes.html>`_. All LLVM releases may
25be downloaded from the `LLVM releases web site <https://llvm.org/releases/>`_.
26
27For more information about libc++, please see the `Libc++ Web Site
28<https://libcxx.llvm.org>`_ or the `LLVM Web Site <https://llvm.org>`_.
29
30Note that if you are reading this file from a Subversion checkout or the
31main Libc++ web page, this document applies to the *next* release, not
32the current one. To see the release notes for a specific release, please
33see the `releases page <https://llvm.org/releases/>`_.
34
35What's New in Libc++ 8.0.0?
36===========================
37
38New Features
39------------
40
41API Changes
42-----------
43- Building libc++ for Mac OSX 10.6 is not supported anymore.
44- Starting with LLVM 8.0.0, users that wish to link together translation units
45  built with different versions of libc++'s headers into the same final linked
46  image MUST define the _LIBCPP_HIDE_FROM_ABI_PER_TU macro to 1 when building
47  those translation units. Not defining _LIBCPP_HIDE_FROM_ABI_PER_TU to 1 and
48  linking translation units built with different versions of libc++'s headers
49  together may lead to ODR violations and ABI issues. On the flipside, code
50  size improvements should be expected for everyone not defining the macro.
51